feat: 104. Maximum Depth of Binary Tree

Author: gwbaik9717

maximum-depth-of-binary-tree/gwbaik9717.js

@@ -0,0 +1,39 @@
+// Time complexity: O(n)
+// Space complexity: O(n)
+
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+var maxDepth = function (root) {
+  let answer = 0;
+
+  const dfs = (current, depth) => {
+    if (!current) {
+      return;
+    }
+
+    if (answer < depth) {
+      answer = depth;
+    }
+
+    if (current.left) {
+      dfs(current.left, depth + 1);
+    }
+
+    if (current.right) {
+      dfs(current.right, depth + 1);
+    }
+  };
+
+  dfs(root, 1);
+  return answer;
+};